Marine excavator



N 1953 P. NOTARBARTOLO ET AL 2, 9, 1

MARINE EXCAVATOR 3 Sheets-Sheet 1 Filed July 28, 1948 fz'ezmzizzrZarwzaQ/Za foZedreZZ,

7, 1953 P. NOTARBARTOLO ET AL 2,659,211

MARINE EXCAVATOR 3 Sheets-Sheet 2 Filed July 28, 1948 Pzira/VaiariakiahNov. 17, 1953 P. NOTARBARTOLO ET AL 2, 5 ,2

MARINE EXCAVATOR Filed July 28. 1948 S Sheets-Sheet 5 fiz'zmjzazaridrzh' z? fbiedrell.

AT ORNEY Patented Nov. 17, 1953 MARINE EXOAVATOR Pietro Notarbartolo andCarlo Poledrelli, Rome, Italy Application July 28, 1948, Serial No.41,164

16 Claims. (01. 61-72) This invention relates to a method and. apparatusfor either interring or disinterring submarine cables includingreasonably flexible piping. The

primary object of the present invention is to make it possible to bury acable at a depth below the bottom greatly in excess of what hasheretofore been believed possible and also to bury or to remove a cablewhere the water is quite deep.

An object of the invention is to provide a method of applying powerfulwater spouts from an excavator body having wide latitude of movementwith respect to the cable ship or other naval craft from which the cablelaying or cable removing operation is controlled.

A further object of the invention is to indicate the direction in whicha cable being disinterred is directed in order that the cable ship orother vessel may follow this direction or path.

A further object of the invention is to provide an excavating devicewhich may surround a cable being disinterred and which may moveforwardly with respect to the cable either by its own weight or by meansof auxiliary jets or by small motordriven friction wheels resilientlyengaging the cable; or by any combination of these means, the resultbeing that the excavating device easily follows the direction of thecable to be disinterred. A preferred form simultaneously cuts an annularpath around the cable, and in addition removes the material directlyabove the cable facilitating its recovery.

A still further object of the invention is to provide a method ofburying or disinterring a cable by means which create a basin in the seafloor, rather than a mere trench, the basin moving progressively. V

In the drawings: c

Figure 1 is a diagrammatic view illustrating a. vessel disinterring acable at the front end and simultaneously interring a substitute cable.

Figure 2 is an elevation partly in central vertical section of apreferred form of excavator.

Figure 3 is a front elevation of the excavator, half in verticalmid-section.

Figure 4 is a slightly modified excavator shown as supported by a cableto be buried.

Figure 5 is a further modified form of excavator.

Figure 6 is one of a series of auxiliary ejectors.

Figure 7 is a horizontal section above the pivot rods of the preferredform of excavator.

' Up to the present time it has frequently happened that a cable hasbecome so deeply embedded that it is cheaper to lay a new cable than todisinter the old one. An exception naturally exists where some fault hasto be repaired or the I terminal has to be shifted slightly, and inthese cases it is necessary to go to the heavy expense required underold practice. Another difficulty is that where the water depth isreasonably shallow, the draft of a suitably equipped cable ship is toogreatto permit navigation at that depth and this has required the use ofsmaller craft, the ability of which is seriously limited. Another pointof diificulty has been that where a cable was buried deeper than say afoot, the pulling on the cable itself to free it frequently exceeded thelimit of elasticity of the protective armor of the cable and it wouldbreak.

The present invention is based on the thought that a cable can be laidat almost any reasonable depth with much convenience and even for adistance of several miles from the shore, if we employ powerful streamsof water applied from nozzles in an excavator that is not rigidlyconnected with the vessel and hence can precede the vessel and entershallow waters below the draft of the mother ship.

The present device can readily lay a cable two feet beneath the bottomand this is generally considered a sufficient distance to insure againstpossible mishaps caused by tide or by mechanical actions. The water jetmethod here illustrated is capable of burying a cable two or three timesthat depth and can as readily remove a cable buried a fathom beneath thesea floor. It can operate at pressure up to fifty atmospheres.

Referring particularly to Figure 1 showing the general idea, a cableship or other vessel I0 is equipped with a pump II, a compressor I2, acable winding device M, a towline I 6, and of course the usual devices(notshown) including dynamometer, sonic depth finder, profile recorder,cable length computer, etc. At the front end of the ship the excavatoris numbered 20 and it sur rounds a cable 2| which in this case is beingdisinterred and wound on spool [4 as it is recovered. An air pipe 23leads from the compressor to furnish bubbles 54 to indicate on thesurface of the water the direction of the cable and to operate a smallcompressed air motor driving a pair of wheels 55 engaging the cable 2|to move the excavator 20 forward on the cable. One or more water pipes22, either single or multiple, lead from the pump II to the excavator.The excavator 20 is shown as throwing a forward annular main stream 24and an auxiliary stream 25, the former surrounding the a buried cable 2|and the latter clearing away the material above the cable.

At the rear of the ship it an excavator (it is being pulled by towlinel8 and is burying a cable 3| which has previously been lightly laid onthe sea floor or bottom 32. Naturally a cable can be buried as it isunwound. As. in the previous case, the jets of water from the excavatorclear a basin for the cable and the natural action of the sea buries thecable at the depth to which it is pulled. down by the weight of theexcavator 3t and its applied ballast. The depth at which. the cable 3|will be buried will also dependupcn.

the tautness of the towline l8 and its length;

In Figure 2 the excavator 25ris shownirpits preferred form. It consistsmainly of three ma:

ior portions: a top portion 4| of the main .body..

a similar cooperating lower portion 42; and a readily removablesecondary ejector 43,. These ing; from an cutletbox 5Lwhich is supportedby the. cable. 2 i: and a, loose clamping... plate 5.1. secured bybolts- 53 so. that. the, outlet box may readily. be removed from. the:cable. The outletbox tiireceives; its water. supply, from main wate ninean eceives. infill. a nine. 23.- shown separa e ion. onv nience ofillustrati n but a tually cate nsi e or. ached: to the. mai Wate p ne2am tinny; eas s. th air. nine 23- c mpre s d air is: su n d o ausbuhblesesuchz as'indicated. at to. to riseto the sur ace. tosho t e dction-t wn the. cabl extends. and the. air: also. drives, asrnall. com;pressed air motor within thecutlet box, and dniving 'the friction ortraction wheels idon; opilov e-side of t e cabl When. the: ra tiowheelsii are used,.the=outlet.b.ox til issecured to the main; p rtion.cub -exca ator. by" a ri i rod: 1 b whe e th se. wheels are. omitted:or. are. driven, from the. excavator. body, aszis. generally thecaselhe. rodisireplaced by a: simple wire. which. under tension pulls,the outlet box along behind the excavator; as it, ad-. vancea along,the-cable.- 2i. gravity. by auxil ary c r jets 4am; nth wheasyie dinalven: gag-ingthe. cable:v Within. the outlet box. is} tvalve/independently. contrcllingtheflow oj;water th pipeflit This-valve.is. indicated by lever 5,8, whichcan-manually be controlled by, thediverwhoeene a yompan s the expediti n,- or. in our. later. models thisvalve. is electrically OQIL- trollediromthe ship. .any. well. known,fashion.

As. best. seen in Figure 3,. attire, left the upper sectiondlandthelowensection rilareieach com: n e n th mselves. having, alar e. cl ar.cyline dr el. ten nait and hinge. on. each ther. by e th r qi' vzq i trode i t er or bo of which canreadily beireniovedi from the lugs 5'1 and52, one; pair on theuppenporticnand the other-pair onthe lower portion.Ingt-hisway the= two portions are heid together forming a hollowfrusto-conical body. The inner wall 63 onea'chi portion is: cylindrical.while the outer.

waliiBk-is conical; While; the water enters: the top section: thru pipe-543M181 the; bottom section thru pipetfi, it, emerges as an annnlanjetor stream 24; as, thQYWfi-llfil passes thru; the arcuate, slits $5; of.practically? 1808 each. A; ballast. preferably oi, lead; surrounds; an,angle 0t 60}? or. thebottom of, the excayator and, additional weightssuclras. 611111216; be, applied, depending. of course upon. the, depthwhich the cablelies am ne p d of. r v ofthe excavator.

As the pull of the" winding device M; keeps the cable 2! from assuming acatenary form, the inclination of the cable is such as to cause thevertical component of the weight of the ballasted body to be sumcientlygreat as to counterbalance the reaction of the annular jet, hence theexcavator will, in absence of either traction wheels or reverse jets,advance along the cable in accordance with the amount of ballast and theinclination; of; the cablemodified'by the speed of the mother ship. Itwill-be noted that, differing from all previous devices, the advance ofthe excavator is generally quite independent of the. advance of theship. With the traction wheels 55 in use the excavator 28 may moveintothfillow. water while the cable ship remains indeep water.

The. auxiliary ejector or nozzle G3, fed thru pipelifi, fits in apiercedlug 88 rising from the upper portion l! near the annular nozzle 65 andmay consist of a mere conical pipe such ashli3. having a, vertical slot.ll preferably broken into. a number of portions bysmall partition crbridges. 12. For: sandy bottoms this type ofsecondary ejectoris. verysatisfactory and four partitions dividethe. secondary nozzle, into. fivelone slots, hese beinadirected upwardly andabit. forwardly. Where. the.bottom is. muddy; the type. oi; secondary ejector shown. in Figureefiis, a bit more satisfactory. The flexible pipe 79; is threaded. to.receive. a union l3: and the; type; of lector showninEisure 6 isnmerelyfiaring, being of. the. samevddth as the. ejectoreii: but rising asat.lttda fanshapeand-having thesameslotsildivided bythe. partitions '52..The Water. blade in this case i directed generally forward, and.somewhat. upwardly. Av small: boss, 1i fits into thaholein lugfiland maybe secured in place by any ordinaryfastening.means- The pipe 19. permitsangular adjustment of the secondary ejector. whether. arsimplepipc like,123. or the fan shape showninFigurefi, or any of theinter-- mediatenozzles... It. isthe. work of but minutes to substitute one..-secondary. ejector for another, here being, anurnber of them, in arset.

InFigure. 4 a. somewhat. modified. ejector; is illustrated, this. formbeing particularly suited tolaying. a cable... The. cable 3i as shown:has already. been laid upon thebottom and; the-excavat'or .30.supportedby this... cable, inv fact resting directly. upon, it, the,support being: by a carriageaflfl, inwhieh are pivoted three or morewheels 8| of a shape to fit. the'cable 3!. The

excavator, has. a. bracket, 82- turning' freely on the. central.pivot,84. and a shackle=85 of generally U -shal1e turns, freely. about.the same pivot 8d. The, towline, l6 preferably endsin a chain 85 to giveadded weight and we freely surround the chain at times with a steel;pipe- 81 to act as. a-further. ballast. The forward nozzles, arenumbered 88; and-t d wnwardlydirected: nOZr zles are; numb red.- Bfl. prferablyone' row or ozzl 89. bein oneach; side. and therebeing butasingle vertical; row out: nozzles 88%., The

maller. ho s-.- 90. ar preferably directed meaft and aid materially inclearing theimaterial while. dieginethe trench. Inthis: case the weight:of the excavator 3.0,with-or without addedballast pulls, the. cable; 31:down to, the desired" depth. In this particular modification awater-pipe. 9.1" leading, on one. side controls, the front: nozzles 8.nda similar pipe. on the-opposite side: controls the nozzles, an oneaehsidel aswell as the flow thruthe smaller holes 90., The: velocity ofiiow is controlled by the speedof therpumps :feedmg the dual. line 22aenclosing. thepipeslil.

' There are times when the depth at which it is desired that the cableshall be buried or the sea depth is so great that the interference 9;.several pipes makes it advisable to substitute a self-contained unit.The modified form of excavator shown in Figure receives electricalcurrent thru the towline [6 connected to the shackle 85 pivoted to thecarriage 80 as before. In this particular modification the water jetsare all supplied by an electric pump 95 having an intake 96 anddischarging thru a pipe 91, successively to the front nozzle 98, theauxiliary nozzles 99, the bottom nozzles I00, and the exit end of thepipe. In this modification the pump constantly discharges water whichflows rearwardly as indicated at l0l which aids in moving the excavatorforward. The amount of water delivered to the front nozzles 99, or tothe intermediate nozzles 99, or to the bottom nozzle I90 is controlledby valves I03 and I04 electrically operated thru current wires withinthe armored cable I05, leading from the towline It to the excavator bodywhich in this case is quite heavily armored as indicated at I06 to'givevery considerable weight and also to withstand the great pressures towhich this'particular modification will be subjected.

Neither of the two valves are ever closed completely but the amount ofclosure determines the relative amount of water discharged thru thefront nozzle or the other nozzles, there always being some discharge atI01. As in the other modification, the idler wheel I98 merely preventsthe carriage 80 from leaving the cable 3| on which it is supported. Asperfectly obvious-this device will inter a pipe just as well as a cablewhere the pipe has the necessary amount of bending which can be ratherslight when the towline I6 is of considerable length. The pump 95 is ofvariable speed type, draws in the sea ring either a cable being payedout or a cable previously laid on the sea floor. The main nozzle 98consequently may be directed slightly upward as shown or at a steepinclination to direct its stream across the cable.

What we claim is:

l. The method of recovering a buried submarine cable or pipe whichconsists in progressively discharging a substantially annular water jetroughly coaxial with the buried cable, raising the free end of thecable, and simultaneously discharging a water jet upwardly and forwardlywith respect to the axis of the annular jet so as to remove theoverhanging materials of the sea floor above the buried cable.

2. The method of laying a cable or pipe below 3. The method of claim 2in which the basin is cut by means of jets of water at high velocity,certain of said jets being directed vertically downward below the cablein the basin to insure the formation of a basin at least deeper 6 belowthe sea fioor than the desired depth of the cable, other jets locatedbelow the cable in the basin being directed forwardly whereby to form aconstantly moving basin and prevent the formation of a-tunnel.

4. The method of claim 2 in which the basin is cut by means of anannular water jet substantially coaxial of the payed out cable andsurrounding the cable in the basin.

5. The method of claim 2 in which the cutting of the basin is by meansof a series of jets of water at high pressure and at different angleswith respect'to horizontal and vertical and varying the velocity of thewater thru the series of jets independently of each other, so as to digthe basin deeper or shallower as may be desired.

6. In a ship controlled submarine excavator, for burying or excavating acable, a body supported at least in part by the cable, means fordischarging a stream of high velocity water thru the body adjacent thecable to cut a basin, and means for moving the body forwardly along thecable independently of the movement of the ship.

7. The device of claim 6 in which the body is suspended from a carriagemovable upon the cable.

8. The device of claim 6 in which the means include motor driven memberswhich engage the cable to propel the body along th cable.

9. In a device for burying a cable beneath the sea floor, a ship, acable extending from the ship to the floor, a carriage resting upon thecable, a body suspended from the carriage, a towline secured to the shipand pulling the carriage along the cable, a motor-driven pump within thebody drawing water from the sea and discharging the water thru a systemincluding a water conduit having an exit end at the rear of said body toaid in advancing the body, a forward nozzle at the front of said bodyfor cutting a basin in the sea floor in advanc of the body and below thecable, an auxiliary nozzle directed downwardly to deepen the basin, avalve between the two nozzles, and a second valve between the auxiliarynozzle and the exit end, said valves controlling the relative amounts ofwater discharged thru the two nozzles and thru the exit end whereby tomake the basin deeper or shallower and thus determine the depth at whichthe cable will be buried as the natural action of the sea replaces thesea floor as the basin moves in thedirection of the yet-unburied cable.

10. A device for disinterring a cable or pipe buried beneath a seafloor, comprising a shell having a forward annular nozzle surroundingthe cable being freed, and means for conveying water under pressure tothe shell and thru the nozzle, in which the shell is formed by twogenerally similar sections together forming a truncated cone, eachsection discharging thru an arc of approximately one section above thecable, and the means includes a pipe for each section whereby thedischarge of water may be from the upper section alone, the lowersection alone, or from both sections together.

11. A device for disinterring a cable or pipe buried beneath a seafloor, comprising a shell formed of two generally similar sectionstogether forming a truncatedcone, each section with a forward opening toform half of an annular nozzle, a high pressure water pipe for each ofthe two sections, an auxiliary nozzle and a third pipe leading to saidauxiliary nozzle, said auxiliary nozzle throwing a jet or blade of waterforwardly 1 ancht-imvandiyto:removeeverheneingimaterialiM theasearfioerr12." The device ofclaim; 10 with meansnflxed with respect to the shellfor moving the shell away from the freed portionni-the pipe-or-cable andnward: the; stihaiburied hortion;

l3; 'I-'he device of claim; 121m which thee-hell advancing meansyieldinglyl engages; the cable; or pipe and is motor driven:

15 The device of claim 11 with. rollers. at a fixed-distance from theshell yieldingly engaging the cable-or pipe, and means to drive therollers whereby the shell andtheth-reje pipesmay bead. vameed: along; thcable-nor pipe, independently of mevementof a; mother vessel taking inthe cable or pipe asilnis' disin cd;

115 A. submarine excavator comprising a, body, a va riahle speed pumpwithinthe body,:an intake for leading seawater to the pump, a conduit;fed by the pumpdischarging to the-sea in rear of the excavator, nozzlesdischarging forwardly and downwardly from the conduit through the lowernortiqrr of; the body, ereversiible nozzl'ezvat the fprwa rd-end-ci theconduit; and means for altering the-: relative a-mcunts of waterdischarged by the rear, 'front and intermediate nozzles toexca vajoe a;shallower or deeper bain beneath the ea 11.

15;. An excavq ter for burying azsixbmarfine 'aible orderdisinterring a;buriedscable, controlled from 3;; mother vessel butv operatingindependently thereof; comprising "a: body supportedgeit lea-stain partby theacable, means for movingrtheihody on the ca-ble independently ofthe movement of the mother vessel; aplurality of. water'jets extendeingfromthe b0dy,- cnecjet discharging: above; the centerline of e the bodyandamother jet: digch'arg: hag-below; such centerline, a pump fondischarging water at high, pressure through: the jets; means;- foraltering at: will. the relative amount; of water passing through-the181351130 cutzthei searfloor at a greatercra less angletcuformearbasin'ordesired depth, a'nde thirdnjetdischarging water in rear of the; bodyto" aid: immovlng. the body' for-' ward to advance it on the cable;

PI'ETRO NDTARBARTOLOZ CARLO POIJEDRELIL II.

re ce C e n e e t this; inherit FOREIGN PATENTS? Number I Cb'un Dane..5, 5 q rm l iy W" 31332 70.51430; Ge many -t---.---'-.---- or 1941

